It relates more particularly to an endless flexible belt track formed from an elastomer and comprising a steel cable spirally wound and embedded in the thickness of the belt to form more or less parallel longitudinal turns, as well as at least one layer of wires embedded in the thickness of the belt toward the inside and/or outside relative to the turns of the cable.
The wires comprising the layer or layers are cables, generally of steel, having a smaller diameter than the spirally wound cable. These wires may be formed from a single strand or filament, preferably from several assembled strands or filaments.
Endless flexible belt tracks of this type are already known and are being used increasingly to replace classical flexible belt tracks consisting of metal links joined together. These flexible tracks are used in numerous all-terrain vehicles such as agricultural machines and public works vehicles. A track of this type is known in particular from the patent FR-A-2 711 959 (93 13211), filed in the name of the applicant.
The endless flexible belt formed from an elastomer, generally with a natural rubber base, is wound round two end wheels of the vehicle, at least one of which is the driving wheel. The flexible belt is generally fitted on the outside with studs to improve adherence to the ground, and the inside with means for engaging with the driving wheel or wheels.
The belt is reinforced not only by the steel cable hectically wound in the thickness of the belt, but also by layer of wires which are embedded in the thickness of the belt, towards the inside and/or outside relative to the turns of the cable. Each of these layers consists of wires, in most cases of steel, which extend parallel with each other and which have a diameter smaller than the steel cable.
The design of these reinforcing layers, which serve as windings, present numerous practical difficulties.
In fact, these layers must be able to resist the extremely high stresses to which the track is subjected because of its winding tension and the obstacles it encounters. It should be remembered that the tension of the track is generally between 3 and 12 tons, and that the track is subject to major stresses in different directions, particularly when on a slope or bank or when it passes over obstacles of varying sharpness that are likely to damage it.
The tracks of prior art do not provide a solution to this problem.